Geoelectrical investigations for aquifer characterization and geoenvironmental assessment in northern Morocco

Abstract

The Mediterranean mountains of Morocco (“Rif”) show an intense sensitivity to hydro-climatic hazards. Hydrologic achievements are thwarted by a series of constraints that request strategic consolidation. The acceleration of socioeconomic activities is causing an increasing pressure on water resources that are already facing insufficiency and degradation problems. This paper aims at geophysical characterization of the most important intramountainous alluvial aquifer on the Rif, Ghis–Nekor. Its electrical and hydrogeological properties are investigated through a correlation of 2D electrical resistivity tomography (ERT), vertical electrical sounding (VES) and borehole data. The results have shown that this monolayer coastal aquifer is constituted of large coarse sand, gravel and pebble deposits that overlay substrata of different hydrogeological and electrical types. A geoenvironmental survey was also carried out in the coastal zone and near the uncontrolled waste landfill of Beni Bouayach. The 2D ERT profiles indicate an increase of marine water intrusion (over 2 km) particularly on the eastern bank of the Nekor river. They also show a spread of the landfill leachate flow path beyond 1 km in the direction of the groundwater flow (to the North), towards an area of hydrogeological interest located east of the city of Imzouren. These results imply a socioeconomic and environmental vulnerability that evokes an immediate intervention to restore weakened equilibrium.